chapter 21 The Heart

These flashcards cover critical vocabulary related to the structure, function, and physiology of the heart.

Function of the Heart

Pumping blood to supply tissues with oxygen and nutrients.

Atria

The two upper chambers of the heart that receive blood from veins.

Ventricles

The two lower chambers of the heart that pump blood out of arteries to the lungs and body.

Pulmonary Circuit

Carries carbon-dioxide rich blood from the heart to the lungs and returns oxygen-rich blood to the heart.

Systemic Circuit

Transports oxygen-rich blood from the heart to the body's cells and returns carbon dioxide-rich blood back to the heart.

Pericardium

The membrane that surrounds the heart, consisting of an outer fibrous layer and an inner serous layer.

Pericardial Fluid

Fluid produced by the pericardium that reduces friction between the heart and the pericardial cavity.

Epicardium

The outer layer of the heart wall, also known as the visceral layer of the serous pericardium.

Myocardium

The middle layer of the heart wall composed of cardiac muscle tissue.

Endocardium

The inner layer of the heart wall made up of simple squamous epithelium continuous with the blood vessels.

Cardiac Muscle Tissue

Muscle tissue that can contract without nervous system stimulation, interconnected by intercalated discs.

Intercalated Discs

Specialized connections between cardiac muscle cells that allow for direct electrical connection.

SA Node (Sinoatrial Node)

Pacemaker of the heart that initiates electrical impulses for heartbeats.

AV Node (Atrioventricular Node)

Delays electrical impulses from the atria before they spread to the ventricles.

Chamber of the Heart

Each of the four sections of the heart: right atrium, left atrium, right ventricle, left ventricle.

Great Vessels of the Heart

Major blood vessels that include the aorta, pulmonary arteries, and vena cavae.

Atrioventricular Valves

Valves located between the atria and ventricles (e.g., tricuspid and mitral valves).

Semilunar Valves

Valves located at the exit of the ventricles (e.g., aortic and pulmonary valves).

Coronary Arteries

Arteries that supply blood to the heart muscle itself.

Myocardial Infarction

A heart attack that can occur due to blood supply blockage to heart muscle.

Cardiac Cycle

The sequence of events in one heartbeat, including systole and diastole.

Systole

Phase of the cardiac cycle when the heart contracts.

Diastole

Phase of the cardiac cycle when the heart relaxes.

Cardiac Output

The volume of blood the heart pumps per minute.

Heart Rate

The number of heartbeats per minute.

Heart Innervation

The process by which the autonomic nervous system regulates heart rate and contraction strength.

Arrhythmia

Abnormal heart rhythm that can occur due to issues with pacemaker cells.

Bradycardia

A slower-than-normal heart rate.

Tachycardia

A faster-than-normal heart rate.

Coronary Circulation

Circulation of blood to the heart muscle via coronary arteries and veins.